Field of the Invention
This invention relates to antennas for wireless communications, and more particularly, to a WiFi patch antenna including dual opposing u-shaped slots and configured for 2.4 GHz and 5.2/5.8 GHz band resonances.
Description of the Related Art
Microstrip patch antennas are well known and used in the art.
Generally, a microstrip patch antenna generally includes a thin sheet of conductor (typically copper, but often can be another conductive metal). The conductor is often positioned on a top surface of a substrate, and the patch/substrate combination is usually applied above a ground plane. A feed substrate may be combined with the ground plane depending on the desired characteristics.
There is a significant demand for patch antennas designed for Wireless Local Area Network (WLAN), otherwise known as “Wi-Fi”, including resonances at 2.4/5.2/5.8 GHz.
Microstrip patch antennas, including variations with slots and without slots, are disclosed by Sivakumar et al., “Bandwidth enhancement of rectangular microstrip patch antenna using slots”, IOSR Journal of Electronics and Communication Engineering (IOSR-JECE) e-ISSN: 2278-2834, p-ISSN: 2278-8735. Volume 6, Issue 1 (May-June 2013), PP 07-10. As disclosed by Sivakumar, the dimensions of the radiating structure, patch width, and the feed point position are chosen according to the required frequency of operation.
Further, Ghalibafan et al., “A NEW DUAL-BAND MICROSTRIP ANTENNA WITH U-SHAPED SLOT”, Progress In Electromagnetics Research C, Vol. 12, 215{223, 2010″, discloses a microstrip antenna with a u-shaped slot. As disclosed by Ghalibafan et al., in some applications, it is desired to have a dual band or multiband characteristics. These characteristics can be obtained by coupling multiple radiating elements or by using tuning devices such as varactor diodes. However, these methods make antenna more complicated. A simple method to achieve the dual band characteristic in a microstrip antenna is embedding a slot in the patch as the structure proposed in which the radiating patch includes a pair of step-slots. In microstrip antennas, embedded slots can also be used to enhance the impedance bandwidth of a single band antenna.
Other examples of WLAN patch antennas are disclosed by Wang et al. “A NOVEL DUAL-BAND PATCH ANTENNA FOR WLAN COMMUNICATION”, Progress In Electromagnetics Research C, Vol. 6, 93 {102, 2009.
While microstrip patch antennas are widely known and form a crowded art, there remains a need for new antenna structures for providing additional resonances, smaller form factor, improved efficiency, improved impedance characteristics, and other improvements as would be recognized by those with skill in the art.